/* Macro expand takes data set with y successes from n trials per row */
/* and expands it to have y rows with y=1 and n-y rows of y=0.        */
/*                                                                    */
/* Hugh Crews, June 2008                                              */
/*                                                                    */
/* Example call: %expand(dataset=one,successes=y,trials=n);           */
/*                                                                    */
/* data one;                                                          */
/* input study $ trt $ y n;                                           */
/* cards;                                                             */
/* solomon celeb   18 1356                                            */
/* solomon placebo  3  679                                            */
/* pfizer  celeb    2  285                                            */
/* pfizer  placebo  0  140                                            */
/* presap  celeb    9  933                                            */
/* presap  placebo  3  628                                            */
/* proc print;                                                        */
/* %include 'K:expand.binomial.data.txt';                             */
/* %expand(dataset=one,successes=y,trials=n);                         */
/* proc print;                                                        */
/*                                                                    */
/* Obs     study       trt       y      n                             */
/*                                                                    */
/*  1     solomon    celeb      18    1356                            */
/*  2     solomon    placebo     3     679                            */
/*  3     pfizer     celeb       2     285                            */
/*  4     pfizer     placebo     0     140                            */
/*  5     presap     celeb       9     933                            */
/*  6     presap     placebo     3     628                            */
/*                                                                    */
/* Obs     study       trt      y                                     */
/*                                                                    */
/*  1     solomon    celeb      1                                     */
/*  2     solomon    celeb      1                                     */
/*  3     solomon    celeb      1                                     */
/*  .      .         .        .                                       */
/*  .      .         .        .                                       */
/* 4019    presap    placebo    0                                     */
/* 4020    presap    placebo    0                                     */
/* 4021    presap    placebo    0                                     */
/*                                                                    */

%macro expand(dataset,successes,trials);

proc means data=&dataset. noprint;
where &successes. ne . and &trials. ne .;
var &successes.;
output out=n n=n;
run;

data null;
set n;
call symput('num',n);
run;

%do j=1 %to &num.;
data aaaa;
set &dataset.(firstobs=&j. obs=&j.);
zero=&trials.-&successes.;
one=&trials.-zero;
call symput('one',one);
call symput('zero',zero);
run;

data aaaa&j.;
set &dataset.(firstobs=&j. obs=&j.);
drop &successes. &trials.;
%do l=1 %to &one.;
response=1;
output;
%end;
%do l=1 %to &zero.;
response=0;
output;
%end;
run;
%end;

data &dataset._expanded;
set
%do j=1 %to &num.;
aaaa&j.
%end;
;
rename response=y;
run;

proc datasets;
delete aaaa:(gennum=all);
run;
quit;

%mend;